Remove Enum from Float and Double

[Roman Cheplyaka]

* Johan Tibell <johan.tibell at gmail.com> [2013-06-11 15:03:10-0700]
> On Tue, Jun 11, 2013 at 3:00 PM, Roman Cheplyaka <roma at ro-che.info> wrote:
> 
> > Does such thing as a deprecation pragma for an instance exist?
> > What triggers it?
> >
> 
> I don't know. We'll need one if we're going to deprecating core instances.
> Just deleting them is not an option (as it gives users with large code
> bases no time to migrate).

On a second thought, it does seem feasible. The warning would be
triggered at the point where the (implicit) class dictionary is used to
invoke a polymorphic function.

This, however, requires input from the type checker. All previous
deprecations have been only name-based, IINM.

Roman